Wobble pump



y 14, 1963 LA VERGNE SMITH 3,089,424

WOBBLE PUMP Filed g- 16, 1957 3 Sheets-Sheet 1 y 1963 LA VERGNE L. SMITH 3,089,424

WOBBLE PUMP Filed Aug. 16, 1957 3 Sheets-Sheet 2 y 1963 LA VERGNE L. SMITH 3,089,424

WQBBLE PUMP 3 Sheets-Sheet 3 Filed Aug. 16, 1957 3,089,424 WQEBBLE PUMP La Vergue L. Smith, Reseda, Califi, assignor to I elecomputing Corporation, a corporation of California Filed Aug. 16, 1957, Ser. No. 678,579 3 Claims. (Cl. 103-133) This invention relates to a rotary pump of the general type incorporating the following basic combination: an annular chamber having two opposite side walls and two circumferentially spaced ports; a hub or rotor concentric with the annular chamber; a circumferential impeller blade on the hub inclined relative to the axis of the pump chamber and shaped for simultaneous moving sealing contact with the two side walls of the chamber as well as the circumferential chamber wall; and a partition or divider wall spanning the annular chamber between the two ports to separate the low pressure zone of the pump in the region of the inlet port from the high pressure zone in the region of the outlet port. As the inclined impeller blade progressively shifts its regions of contact with the annular pump chamber in one circumferential direction, it cooperates with the divider wall to divide the chamber into compartments which expand sequentially in communication with the input port and contract sequentially in communication with the output port. Such a basic combination, which is found, for example, in the Wicha Patent 1,946,344, operates with positive displacement of the fluid and has the inherent advantage of being capable of operation without creating troublesome pulsations in the discharge flow.

In the usual embodiments of this basic combination, one difficulty is that the frictional resistance by the moving parts of the pump is high. In some embodiments, for example, the impeller blade rotates in sliding contact with the walls of the chamber with high rotational resistance between the blade and the chamber surfaces.

In the usual embodiments, moreover, it is difiicult to maintain effective sealing action where required between relatively moving parts. In a common arrangement, for example, the impeller blade rotates through and is straddled by a partition member or divider wall that reciprocates to follow the oscillating rotation of the inclined impeller blade. It is difficult to prevent leakage through and around the reciprocating partition, and especially so because the maximum and minimum fluid pressures exist on the opposite sides of this partition. To minimize such leakage it is necessary to manufacture the moving parts with small dimensional tolerances.

A third difiiculty is the progressii e drop in efficiency of such a pump over an extensive period of time caused by undue wear between relatively sliding parts. Such wear, causes progressively increasing leakage across the reciprocating partition as well as between the impeller blade and the walls of the annular pump chamber.

The present invention meets these difiiculties by avoiding continuous unidirectional rotation of either the impeller blade or the hub on which it is mounted and by employing a stationary partition or divider wall without any slot therein for the impeller blade. The impeller blade wobbles in a circumferentially progressive manner without actual circumferential rotation and the impeller blade is slotted to straddle the divider wall instead of the divider wall straddling the impeller blade.

Frictional resistance at the peripheral circumferential surface of the impeller blade is greatly reduced because on each cycle of operation any given point on that surface in contact with the circumferential Wall of the annular purnp chamber merely reciprocates across the narrow width of the pump chamber instead of sliding around the whole circumference of the circumferential pump wall. Thus, frictional resistance at the blade circum- 3 g Patented May 14, 1963 ference is reduced many fold. The hub that carries the impeller blade has a spherically curved surface journaled in a spherically curved bearing and here again frictional resistance is reduced in the same manner, since any given point on the hub merely oscillates in the bearing between two closely spaced limits in each operating cycle instead of traversing the whole circumference of the bearing.

Frictional resistance between the impeller blade and the side walls of the annular pump chamber is reduced to even greater degree because rolling contact is substituted for sliding contact. The surface of the impeller blade actually rolls along the surface of each of the two side walls of the annular pump chamber, nothwithstanding the fact that the impeller blade itself does not rotate circumferentially.

Sealing at the divider wall between the maximum and minimum pressure zones of the pump is simplified because there is no slot through the divider wall and because the divider wall is stationary instead of reciprocating. With the divider wall stationary it is a simple matter to seal the juncture between the divider wall and the chamber wall. It is also a simple matter to form the radially inner end of the divider wall with a sperically curved edge for sealing contact with the spherically curved surface of the hub. These features of the invention eliminate the need for manufacturing the pump parts to the extremely close dimensional tolerance typical of the prior art.

The problem of reduction in etliciency by undue wear between relatively moving working parts is obviously met by the manner in which frictional resistance is so greatly reduced. It is to be noted that at the divider wall where the maximum pressure differential exists, the only wear is between the divider Wall and the hub and this wear is exceedingly gradual because the hub merely oscillates laterally in a narrow range instead of continuously rotating past the divider wall.

The invention meets the problem of progressive wear and consequent progressive loss of efiiciency not only by reducing friction and relative movement between mutually contacting parts but also by making possible provisions for wear compensation. The divider wall, for example, may be urged towards the spherical hub by spring pressure for wear compensation as well as for the purpose of maintaining sealing efiiciency. Another provision is to wobble the impeller blade by means of actuating force applied in such manner as to tend to rock the blade to cause the blade to press continuously laterally against the side walls of the annular pump chamber. With this lateral pressure there is complete compensation for wear between the blade and the chamber side wall with no loss of sealing efliciency.

A further feature of the invention is that the lateral pressure of the impeller blade against the annular pump chamber walls may be applied in a yielding manner for inherent control over the pressure rises therein. If the resistance .to fiuid discharge from the pump. rises unduly, the impeller blade reacts by momentarily retracting slightly away from the annular chamber walls to release the pressure. Thus, the magnitude of the yielding later-a1 pressure applied to the impeller blade may be selected to limit the pump to any desired predetermined maximum pressure.

A still further feature is that the pump may be used for high temperature installations with an extremely wide range of compensation for thermal expansion and contraction of the working pants. Such compensation is inherent in the use of a divider wall that is yieldingly pressed against the spherical hub and again is inherent in those arrangements in which the impeller blade is yieldingly pressed laterally against the side Walls of the annular pump chamber.

The various features and advantages of the invention may be understood from the following detailed description together with the accompanying drawings.

In the drawings, which are to be regarded as merely illustrative:

FIGURE 1 is a longitudinal sectional view of a combined motor and pump embodying the invention, this motor-pump unit being designed to supply fuel to the fuel line of an automotive vehicle in such manner as to maintain the fuel line under continuous pressure;

FIGURE 2 is a side elevation of a hub and a circumferential impeller blade thereon that are used in this embodiment of the invention;

FIGURE 3 is a transverse sectional view of the pump taken at the juncture of the two sections of the pump housing as indicated by the line 3-3 of FIGURE 1;

FIGURE 4 is a diagram showing the components of actuating force in this embodiment of the invention;

FIGURE 5 is a similar diagram showing how the forces may be changed by changing the angle of a driving face of the pump mechanism;

FIGURE 6 is a fragmentary sectional view showing how the means for actuating or wobbling the impeller blade may comprise a planetary friction drive mechanism;

FIGURE 7 is a similar view showing how the actuating means may comprise planetary gearing;

FIGURE 8 is a view similar to FIGURE 6 showing how the frictional planetary drive may incorporate yielding means to prevent excessive pressure rise in the p p;

FIGURE 9 is a view similar to FIGURE 8 showing how two yielding means may cooperate for the same purpose;

FIGURE 10 is a fragmentary sectional view showing how the actuating means for wobbling the impeller blade may be constructed in another manner to provide a component of force that rocks the impeller blade laterally against the side walls of the annular chamber in a yielding manner to prevent excessive pressure rise in the pump;

FIGURE 11 is a transverse section taken as indicated by the line 11-11 of FIGURE 10;

FIGURES 12, 13 and 14 are diagrams showing how the component of force that presses the impeller blade laterally against the annular pump chamber walls may be varied by varying the inclination of a driving face employed in the arrangement shown in FIGURES 10 and 11;

FIGURE 15 is a view similar to FIGURE 6 showing a planetary frictional drive with spring-pressed conical elements that may be employed to wobble the hub; and

FIGURE 16 is a fragmentary view showing how the annular pump chamber may have parallel planar side walls instead of frusto-conical side walls, the impeller blade having frusto-conical faces instead of parallel planar faces.

FIGURE 1 illustrates an embodiment of the invention for use in the fuel system of an automotive vehicle wherein the liquid fuel is maintained under pressure in the fuel line and is released therefrom by remotely controlled injection valves. The device shown in FIGURE 1 is a unit comprising a pump, generally designated by the letter P and a motor for actuating the pump, the motor being designated by the letter M. The unit has a multiple section housing which comprises two sections 20a and 20b forming the housing of the pump P and two sections 20c and 20d forming the housing of the motor M. Long screws 22 interconnect the housing sections 20a, 20b and 200 with suitable O-rings 24 and 25 sealing the two joints, and shorter screws 26 attach the housing section 20d to the housing section 20c with an O-ring 28 sealing the joint.

The motor M may be a permanent magnet D.-C. motor having stator magnets 30 and having an armature coil 4 32 mounted on a motor shaft 34. The motor shaft 34, which is mounted at its opposite ends in bearings 35 and 36, carries a commutator 38 for cooperation with the usual spring-pressed brushes 40. The brushes 40 are connected to an external terminal 42 and a grounded terminal 44.

One of the features of this particular embodiment of the invention is that compactness is achieved not only by combining the pump and motor in a single unit but also by employing the unit as a fluid passage means in the fuel system, the motor of the unit being designed for fluid flow longitudinally therethrough. One end of the unit has an intake port 45 adapted for connection to a fuel source by suitable conduit means and the other end has a discharge port 46 adapted for connection to a fuel line that leads to the internal combustion engine of the automotive vehicle. The flow passage through the unit from the pump P to the discharge port 46 includes an inner conical annular space 48 at the end of the pump shaft 34 communicating with the pump outlet port 70, an annular space 50 in communication with the space 48, an outer annular space 52 around the armature coil 32 that is in communication with the annular space 50, an outer annular space 54 that communicates between the brushes 40 with the annular space 52, and an inner annular space 55 that communicates both with the outer annular space 54 and the discharge port 46. It has been found that fluid flow through the motor and around the motor armature in this manner does not interfere with the operation of the motor. Fuels for internal combustion engines may be handled in this manner, but in some instances it is desirable to place a screen across the flow passage to serve as an explosion shield to inhibit flame propagation into the pump in the event suflicient oxygen should get into the motor chamber to permit detonation of a highly inflammable fluid fuel.

The essential parts of the pump P include: a spherical hub that is journaled the pump housing and forms with the pump housing an annular pump chamber 62; a circumferential impeller blade 64 that is carried by the hub 60; and a partition or divider wall 65 that extends across a radial portion of the annular pump chamber. As shown in FIGURE 3, an intake passage 66 on one side of the divider wall 65 places the annular pump chamber 62 in communication with the intake port 45, and an output passage 68 on the other side of the divider wall places the annular pump chamber 62 in communication with a pump port 70 that leads to the previously described fluid passage that extends through the unit to the discharge port 46.

The annular pump chamber 62 has an inner spherically curved circumferential wall 72 and two opposite annular side walls 74 and 75. The two side walls 74 and 75 are conically curved and the impeller blade 64 is a flat blade with parallel planar side faces, but it is to be understood that the inner side walls of the annular pump chamber may be flat or planar with the faces of the impeller blade comically curved, or both the inner side walls of the chamber and the side faces of the impeller blade may be of conical curvature. Preferably, the circumferential edge of the impeller blade 64 is spherically curved for sealing contact with the spherically curved inner circumferential wall 72 of the annular pump chamber 62.

The impeller blade 64 is inclined relative to the annular pump chamber 62 in sealing contact with the opposite side walls of the chamber along one diameter of the impeller blade. Thus, as may be understood by reference to FIGURE 1, one radial portion of the impeller blade 64 makes line contact with the side chamber wall 74 and another radial portion of the blade on the same diameter makes line contact with the second side wall 75 of the annular pump chamber. The impeller blade 64 is continuously wobbled to cause its radial lines of contact with the two side chamber walls 74 and 75 to progress continuously in one circumferential direction around the annular pump chamber, the side faces of the impeller blade rolling on the side walls of the pump chamber without circumferential rotation of the impeller blade itself.

As shown in FIGURE 2, the impeller blade 64 is formed with a radial slot 76 to straddle the divider wall 65 and it is apparent that the engagement of the impeller lade with the divider wall in this manner prevents circumferential rotation .of the impeller blade. The divider wall 65 is mounted in a corresponding radial slot 78 in the pump housing and has its inner edge spherically curved for sealing contact with the hub 60. A suitable leaf spring 80 continuously urges the divider wall 65 into sealing pressure contact with the hub 60.

Any suitable means may be employed for operatively connecting the motor shaft 34 to the impeller blade 64 to cause the impeller blade to wobble continuously in the described manner. In the present embodiment of the invention, the hub 60 is provided with a radial operating arm 82 for this purpose and the outer end of the operating arm is moved in a circular orbit by the motor shaft 34. As best shown in FIGURE 6, the operating arm 82 may be in the form of a pin mounted in a diametrical bore 84 in the hub, the bore being formed with a restriction -85. A reduced end portion '86 of the pin extends through the restriction 85 with a shoulder 88 of the pin abutting one side of the restriction and a peened head 90 of the pin abutting the other side of the restriction.

As shown in FIGURE 1, the shaft 34 is formed with a conical enlargement 92 at its end and this shaft enlargement has a peripheral seat 94 in engagement with an enlargement '95 on the end of the operating arm 82'. In this arrangement it is contemplated that the enlargement 95 on the end of the operating arm 82 will normally remain fixed relative to the shaft enlargement 92 and therefore will be rotated on the axis of the operating arm by the rotation of the shaft. It is apparent that the enlarge ment 95 must be rotatable relative to the impeller blade 64 if the enlargement is to be rotated in this manner with the impeller blade held against circumferential rotation. In this instance, the enlargement. 95 is in the form of a spherical roller that is journaled on the operating arm 82 but, if desired, the enlargement 95 may be integral with the operating arm 82 and the operating arm itself may be journaled in the hub 60.

As indicated diagrammatically in FIGURE 4, the peripheral seat 94 in the shaft enlargement 92 for the spherical roller 95 on the end of the operating arm 82 may be formed with a planar driving face 96 which intersects a plane of rotation of the shaft enlargement in tangential driving contact with the spherical roller. The force F that is transmitted to the spherical roller 95 by the driving face 96 has a tangential component R which drives the operating arm 82 in its circular orbit and has a radial component R which acts on the operating arm 82 to tend to rock the impeller blade 64 laterally into pressure contact with the inner side walls 74 and 75 of the annular pump chamber.

It is apparent that the ratio of the force components R, and R may be varied by varying the inclination of the driving face 96 in the plane of rotation. In FIG- URE 5 for example, the driving face 96a is changed in inclination in the plane of rotation to increase the magnitude of the radial force component R relative to the magnitude of the tangential component R It is the radial component R that provides the desired sealing pressure on the part of the radial blade 64 against the side walls of the annular chamber. It is also to be noted that this driving arrangement inherently compensates for wear on the side walls of the annular pump chamber and on the side faces of the impeller blade 64. Wear on these surfaces merelyresults in corresponding radially outward shift of the spherical roller 95 along the driving face 96.

The manner in which the invention operates for its purpose may be readily understood from the foregoing description. The impeller blade 64 in cooperation with the divider wall 65 creates a succession of expanding compartments in communication with the intake passage 66 and a succession of contracting compartments in communication with the output passage 68, the compartments traveling in succession clockwise as viewed in FIG- URE 3. During the major portion of the operating cycle there are two expanding compartments on-the intake side of the divider wall 65 and two contracting compartments on the output side, but at the particular point of the operating cycle represented by FIGURE 1 there are momentarily only three compartments. One of the three compartments is an expanding compartment on the intake side of the divider wall 65; a second compartment is a contracting compartment on the output side of the divider wall; and the third compartment is an isolated transfer compartment that extends over the lower half of the annular pump chamber 62 as viewed in FIGURE 3. This momentary condition occurs twice in each operating cycle.

FIGURE 6 shows how the motor shaft may be operatively connected to the pump by a planetary transmission mechanism that operates the pump at substantially less speed than the motor. Such an arrangement permits the use of a relatively small high speed motor. The motor shaft 34a in FIGURE 6 is formed with a concentric circumferential end recess 10% that is of circular curvature in cross section for line contact with the spherical roller on the operating arm 82. The spherical roller 95 also makes line contact with a surrounding stationary ring 182 so that rotation of the motor shaft 34a in rolling contact with the spherical roller 95 causes the spherical roller to travel around the inner circumference of the stationary ring 102.

FIGURE 7 shows how planetary gearing may be substituted for the planetary friction drive of FIGURE 6. In FIGURE 7 the end of the motor shaft 34b forms atapered sun gear 194, the apex of the taper being at the point which is the center of curvature of the hub 60-. The tapered sun gear 104 meshes with a planet gear 106 that is substituted for the spherical roller 95 on the operating arm 82. Here again, the apex of the taper is at the point 165. The planet gear 106 meshes in turn with the inner teeth of the fixed ringgear 108. Thus rotation of the sun gear 164 by the motor causes the planet gear 1% to travel around the inner circumference of the fixed'ring gear MP8.

In some instances it is desirable to limit the discharge pressure of the pump by arranging for the impeller blade 64 to press against the side walls of the annular pump chamber in a yielding manner so that whenever the discharge pressure of the pump rises to a predetermined magnitude, the impeller blade rocks laterally out of contact with the two opposite pump chamber walls to slip at least partially through the fluid in the pump chamber instead of propelling thefiuid in a positive manner.

The first described embodiment of the invention functions inherently in this manner as may be understood by reference to the force diagrams in FIGURES 4 andS. In FIGURE 4, for example, if the fluid pressure in the annular pump chamber that opposes the progressive wobble movement of the impeller blade exceeds the magnitude of the force component R the spherical roller 95 will be forced to retract radially inward along the driving face 96, this retraction in effect opening up communication between the intake port 45 and the pump output port 70 to limit the pressure rise in the annular pump chamber.

FIGURE 8 shows how the planetary drive arrangement of FIGURE 6 may be modified to provide a somewhat similar yielding action by the impeller blade to limit the fluid pressure on the discharge side of the pump to a predetermined magnitude. The arrangement shown in FIGURE 8 is largely identical with the arrangement shown in FIGURE 6, as indicated by the use of corresponding numerals to indicate corresponding parts. In this construction, a hollow drive member 110 has a tapered nose 112 which can function in the manner of a cam. This nose 112 is in driving contact with the spherical roller 95 and is seated in a recess 114 in the end of a motor shaft 340. The hollow drive member 110 is slidingly but non-rotatably carried in motor shaft 34 by means of mating splines thereon and therein respectively and is continuously urged axially outward by a confined coiled spring 115.

Normally the pressure exerted by the spring 115 is adequate to cause the tapered nose 112 to hold the spherical roller 95 in driving contact with the surrounding stationary ring 102. If the fluid pressure that resists the progressive wobble of the impeller blade 64 rises to a predetermined critical magnitude, however, the spring 115 is overcome to permit axial retraction of the drive member 110. This yielding action reduces the fluid pressure in the annular pump chamber in two ways. In the first place, the retraction of the impeller blade 64 laterally away from contact with the side walls of the annular chamber causes reduction of pressure as heretofore point ed out. In the second place, the retraction of the spherical roller 95 out of contact with the surrounding stationary ring 102 terminates the driving action on the spherical roller 95 to cause a pause in the progressive wobble of the impeller blade.

FIGURE 9 shows how the arrangement shown in FIGURE 8 may be modified to provide two yielding cam noses instead of one to oppose the rocking retraction of the impeller blade 64 and further shows how fluid pressure may be used in the yielding action. In this construction, the pin that forms the operating arm 82 is extended in length to form an auxiliary arm 82a that carries a second spherical roller 95a. The first spherical drive roller 95 is driven by the hollow drive member 110 in cooperation with the surrounding fixed ring 102 as described heretofore.

At the same time that the spherical drive roller 95 is driven by the tapered nose 112 of the hollow drive member 110, the second spherical roller 95a rolls around a tapered nose 116 of a hollow member 118 that extends into a conical chamber 120 that encloses the auxiliary operating arm 82a. The conical chamber 120 is a low pressure zone since it is in communication with the intake port through a passage 122. A second passage 124 leads to a space 125 at the outer end of the hollow member 118 and communicates with the pump output port 70 to make this space a high pressure zone. The hollow member 118 is slidingly mounted in a bore 126 in the pump casing and is surrounded by an O-ring 128 to seal otf the two zones from each other. A coil spring 130 inside the hollow member 118 acts under compression between the hollow member and a fixed plug 132. Thus, the hollow member 118 is urged axially inwardly into pressure contact with the spherical roller 95a not only by the pressure exerted by the coil spring 130 but also by the fluid pres sure ditferential existing between the conical chamber 120 and the space 125.

Whenever the pressure in the pump chamber 62 that resists the progressive wobble movement of the impeller blade 64 reaches a predetermined high magnitude, the impeller blade 64 rocks laterally out of contact with the side walls of the annular pump chamber to keep the fluid pressure from rising higher. The fluid pressure in the pump chamber 62 must overcome the two springs 115 and 130 in addition to the pressure differential across the hollow member 118 before the two hollow members 110 and 118 will retract to permit the impeller blade 64 to retract laterally from the side walls of the annular pump chamber 62.

FIGURES and 11 illustrate another practice of the invention which is similar to the practice illustrated by FIGURE 1 in that the spherical roller 95 on the operating arm 82 is engaged by a peripheral seat 134 in the end of the motor shaft 34d. The peripheral seat 134 has two opposite side walls 135 and 136 and since the shaft 34d rotates clockwise as viewed in FIGURE 11, the side wall 136 is the driving face of the recess that makes tangential driving contact with the spherical roller 95. The bottom of the peripheral seat 134 is the conical nose 138 of a hollow body 140 that is slidingly mounted in the end of the motor shaft 34d. A suitable coiled spring 142 is housed in the hollow body 140 to urge the hollow body axially outward towards the spherical roller 95. Here again, the conical nose 138 can function in the manner of a cam. The spherical roller 95 seats against both the driving face 136 and the conical nose 138.

In the force diagram in FIGURE 12, the spherical roller 95 is shown in contact with the driving face 136. The driving face 136 intersects a plane of rotation of the motor shaft 34d and is parallel to a radius from the axis of the motor shaft 34d and therefore the component of force F applied to the spherical roller 95 by the driving face is tangential as shown. The component of force S created by the spring 142 is radially outward as shown and the resultant force acting on the spherical roller 95 is indicated at R.

If the inclination of the driving face 136 in the plane of rotation is changed as shown at 136a in FIGURE 13, the direction of the resultant force R will be changed accordingly. By virtue of this change in inclination the driving face 136a acts as a cam surface to urge the spherical roller 95 radially outward to cooperate with the spring 142 in opposing lateral retraction of the impeller blade 64 from the annular side Walls of the pump chamber. Thus, with the force of the spring constant, the change in inclination of the driving face shown in FIGURE 13 increases the critical or maximum fluid pressure in the pump chamber at which the impeller blade 64 will retract laterally to prevent further pressure rise.

FIGURE 14 illustrates the fact that the inclination of the driving face 136 may be inclined to oppose the force of the coiled spring 142. The driving face 136 is inclined as shown at 1361) so that the cam effect of the driving face on the spherical roller is radially inward in 0pposition to the spring 142.

FIGURE 15 shows a friction planetary drive that operates in the same general manner as the friction planetary drive shown in FIGURE 6. The motor shaft 34c has a tapered end portion 144 in driving contact with a tapered roller 145, the tapered roller being in rolling contact with the tapered inner circumferential surface 146 of a surrounding fixed ring 148. All of these tapers converge at the center of curvature of a hub 60a that carries a circumferential impeller blade 64a. The tapered roller is journaled on the end of an operating arm 82b in the form of a pin that is slidingly mounted in the hub 60a. A coil spring 150 inside the hub 60:: acts in compression against a collar 152 on the operating arm 82b to urge the operating arm radially inwardly thereby to maintain the tapered planetary roller 145 in effective wedging contact with the motor shaft and the surrounding ring 148.

FIGURE 16 illustrates the fact that the annular side faces of the pump chamber need not be conically curved and the impeller blade need not have parallel planar side faces. In FIGURE 16, the annular pump chamber 62a has parallel planar side faces 74a and 75a. The impeller blade 64b has conically curved convex side faces for rolling contact with the planar side faces of the annular pump chamber when the impeller blade is wobbled progressively in the previously described manner. 'FIGURE 16 also shows that a divider wall 65a may have parallel side edges 154 slidingly mounted in corresponding grooves 155 to permit unlimited movement of the divided wall against the surface of a hub 60b under the pressure of a leaf spring 80a.

My description in specific detail Of selected practices a rotary member journaled on said am, said rotary of the invention will suggest various changes, substitum mber being movable along a path ith it axis tiQHS and other departures from y disclosure Within of rotation describing a circular orbit to wobble the spirit and scope of the appended claims. the impeller blade in rolling contact with said two I claim: side walls; and

1. In a wobble pump the combination of: a rotary driving means with its axis of rotation passa housing; ing through the center of curvature of said hub,

a hub journalled in said housing and forming theresaid rotary driving means having a substantially with an annular pump chamber having two opporadial driving face in contact with the circular pe- Site annular Side Walls, Said am r having an riphery of said rotary member, said rotary member inlet port and an outlet port; being free to shift outwardly along said driving face a radial dividing wall between said inlet port and outfor pressing the impeller blade against said side let port; walls, the region of said driving face in contact a circumferential impeller blade carried by said hub with said rotary member being inside said orbit to in sliding contact with said dividing wall; impart a radially outward component of force to an arm extending outward from said hub for actuation thereof, said arm having a driven portion of circular cross-sectional configuration, said driven portion being movable along a path with its center of cross-sectional curvature describing a circular orbit to wobble the impeller blade in rolling contact with said two side walls; and

a rotary driving means with its axis of rotation passing through the center of curvature of said hub,

said rotary member to press the impeller blade against said side walls. 3. A combination as set forth in claim 2 in which said rotary member has a spherically curved peripheral surface in point contact with said driving face.

References Cited in the file of this patent UNITED STATES PATENTS said rotary driving means having a driving face 438,187 Roth Oct. 14, 1890 extending along a radius of said orbit in Contact 457,927 Smith Aug. 18, 1891 with the circular periphery of said driven portion 523,761 Christopher July 31, 1894 of the arm, said driven portion of the arm being 801,917 Samin Oct. 17, 1905 free to shift outwardly along said face for press- 941,563 Dilts Nov. 30, 1909 ing said impeller blade against said side walls, he 1,434,741 Goodner Mar. 7, 1922 region of said face in Contact with Said driv 1,888,369 Bassett Mar. 22, 1932 portion of the arm lying inside said orbit to im- 2,083,070 Krueger June 8, 1937 part a radially outward component of force to s i 2,457,417 Trautmann Dec. 28, 1948 arm to press the impeller blade against said sid 2,590,751 Byram et a1. Mar. 25, 1952 walls. 2,603,161 Lloyd July 15, 1952 2. In a wobble pum the combination of: 2,625,914 Pressler Jan. 20, 1953 a housing; 2,636,444 Salgues Apr. 28, 1953 a hub journalled in said housing and forming there- 2,788,747 Hunter Apr. 16, 1957 with an annular pump chamber having two 0pp0- 2,810,348 White Oct. 22, 1957 site annular side walls, said chamber having a 2,860,828 Jonassen Nov. 18, 1958 inlet port and an outlet port;

a itzigtgrfiividing wall between said inlet port and out- FOREIGN PATENTS a circumferential impeller blade carried by said hub 418,465 France July 1910 in sliding contact with said dividing wall; 997,334 France p 12, 1951 an arm extending outward from said hub for actuation thereof; 

1. IN A WOBBLE PUMP THE COMBINATION OF: A HOUSING; A HUB JOURNALLED IN SAID HOUSING AND FORMING THEREWITH AN ANNULAR PUMP CHAMBER HAVING TWO OPPOSITE ANNULAR SIDE WALLS, SAID CHAMBER HAVING AN INLET PORT AND AN OUTLET PORT; A RADIAL DIVIDING WALL BETWEEN SAID INLET PORT AND OUTLET PORT; A CIRCUMFERENTIAL IMPELLER BLADE CARRIED BY SAID HUB IN SLIDING CONTACT WITH SAID DIVIDING WALL; AN ARM EXTENDING OUTWARD FROM SAID HUB FOR ACTUATION THEREOF, SAID ARM HAVING A DRIVEN PORTION OF CIRCULAR CROSS-SECTIONAL CONFIGURATION, SAID DRIVEN PORTION BEING MOVABLE ALONG A PATH WITH ITS CENTER OF CROSS-SECTIONAL CURVATURE DESCRIBING A CIRCULAR ORBIT TO WOBBLE THE IMPELLER BLADE IN ROLLING CONTACT WITH SAID TWO SIDE WALLS; AND A ROTARY DRIVING MEANS WITH ITS AXIS OF ROTATION PASSING THROUGH THE CENTER FO CURVATURE OF SAID HUB, SAID ROTARY DRIVING MEANS HAVIGN A DRIVING FACE EXTENDING ALONG A RADIUS OF SAID ORBIT IN CONTACT WITH THE CIRCULAR PERIPHERY OF SAID DRIVEN PORTION OF THE ARM, SAID DRIVEN PORTON OF THE ARM BEING FREE TO SHIFT OUTWARDLY ALONG SAID FACE FOR PRESSING SAID IMPELLER BLADE AGAINST SAID SIDE WALLS, THE REGION OF SAID FACE IN CONTACT WITH SAID DRIVEN PORTION OF THE ARM LYING INSIDE SAID ORBIT TO IMPART A RADIALLY OUTWARD COMPONENT OF FORCE TO SAID ARM TO PRESS THE IMPELLER BLADE AGAINST SAID SIDE WALLS. 